NpgsqlModelValidator rejects properties mapped via ValueConverter in EF Core 10

Aperta
  • Qualcosa non va?
#3,936 1 commento 0 reazioni 0 assegnatari Vedi su GitHub

I maintainer di solito rispondono entro 1 giorno

Nessuno ha ancora preso questa issue.

Valutazione

Difficoltà
4/5
Tempo stimato
3-5 giorni
Idoneità per principianti
48/100
Tipo di issue
Bug
Chiarezza
Specificata chiaramente
Stato di attività
Attiva
Stack tecnologico
csharp, postgresql
Ambito
backend, database

Direzione di ricerca

Start by reading EF Core 10's ModelValidator.ValidatePropertyMapping and the related relational validation code described in the report; compare their behavior with EF Core 9. Reproduce the failure with the supplied ValueConverter example and check the provider's model validation tests for a suitable regression test. Done means converter-backed properties with a valid provider type mapping pass validation, while genuinely unmapped properties still fail.

Scritto dal modello di indicizzazione a partire dal testo della issue.

Descrizione

NpgsqlModelValidator rejects properties mapped via ValueConverter (no native type mapping) in EF Core 10

Environment
  • Microsoft.EntityFrameworkCore: 10.0.2
  • Npgsql.EntityFrameworkCore.PostgreSQL: 10.0.0
  • .NET target framework: net10.0
  • PostgreSQL: any 10+
Symptoms

A model that maps a readonly struct (or any non-primitive CLR type) to a primitive database type via ValueConverter<TModel, TProvider> fails to build with:

System.InvalidOperationException: The property 'ItemDefinition.Name' could not be mapped
because it is of type 'LocalizedString', which is not a supported primitive type or a valid entity type.
Either explicitly map this property, or ignore it using the '[NotMapped]' attribute or by
using 'EntityTypeBuilder.Ignore' in 'OnModelCreating'.
   at Microsoft.EntityFrameworkCore.Infrastructure.ModelValidator.ValidatePropertyMapping(IConventionTypeBase, IConventionModel, IDiagnosticsLogger`1)
   at MUnique.OpenMU.Persistence.EntityFramework.EntityDataContext.OnModelCreating(...)
   at ...

The same model builds and works correctly under EF Core 9 (Microsoft.EntityFrameworkCore 9.0.x + Npgsql.EntityFrameworkCore.PostgreSQL 9.0.x).

Root cause

EF Core 10's ModelValidator.ValidatePropertyMapping(IConventionTypeBase, IConventionModel, IDiagnosticsLogger<Validation>) runs:

IConventionProperty conventionProperty = structuralType.GetDeclaredProperties()
    .FirstOrDefault(p =>
        (!ConfigurationSource.Convention.Overrides(p.GetConfigurationSource())
            || !p.IsImplicitlyCreated())
        && p.FindTypeMapping() == null);
if (conventionProperty != null)
    ThrowPropertyNotMappedException(...);

FindTypeMapping() returns null for a property whose CLR type has no native relational mapping and whose mapping is established solely through a ValueConverter registered via OnModelCreating. EF Core 9's relational validator consulted the registered converter before this check; EF Core 10 does not.

Confirmed by decompiling both Microsoft.EntityFrameworkCore.Relational 10.0.0 and Npgsql.EntityFrameworkCore.PostgreSQL 10.0.0 with ILSpy.

Minimal reproduction
// Program.cs
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Diagnostics;
using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
using Npgsql;

public readonly struct LocalizedString
{
    public string Value { get; }
    public LocalizedString(string? value) { Value = value; }
    public static implicit operator string(LocalizedString ls) => ls.Value;
}

public class LocalizedStringConverter : ValueConverter<LocalizedString, string>
{
    public LocalizedStringConverter() : base(ls => ls.Value ?? "", s => new LocalizedString(s)) { }
}

public class Item
{
    public int Id { get; set; }
    public LocalizedString Name { get; set; }
}

public class TestContext : DbContext
{
    public DbSet<Item> Items => Set<Item>();
    protected override void OnConfiguring(DbContextOptionsBuilder o)
        => o.UseNpgsql("Host=localhost;Database=test;Username=postgres;Password=postgres");
    protected override void OnModelCreating(ModelBuilder m)
    {
        m.Entity<Item>(e =>
        {
            e.Property(p => p.Name).HasConversion(new LocalizedStringConverter());
        });
    }
}

public class Program
{
    public static void Main()
    {
        using var ctx = new TestContext();
        ctx.Database.OpenConnection(); // Triggers model validation
    }
}

Expected: ctx.Database.OpenConnection() returns without throwing.
Actual: throws InvalidOperationException: The property 'Item.Name' could not be mapped because it is of type 'LocalizedString'.

The same code runs cleanly under EF Core 9 + Npgsql 9.0.4 (the same ValueConverter<LocalizedString, string> is sufficient to make EF Core 9 happy).

Impact

Many production codebases map readonly struct value objects (translated-text wrappers, currency, units of measure, JSON-shaped DTOs) through ValueConverter. EF Core 10's regression in this area forces users either to:

  • mark the type as a complex type via [ComplexType], which has different semantics and does not always work (verified against EF Core 10.0.2 with a converter-backed property on a complex type — the same exception is raised);
  • or to fork the provider with a custom IModelValidator that catches the diagnostic (what I am doing locally to unblock OpenMU — see ffuhr91/OpenMU@fix/npgsql-validator-localizedstring).

Neither is a satisfying fix for the long term.

Suggested fix

ModelValidator.ValidatePropertyMapping(IConventionTypeBase, IConventionModel, IDiagnosticsLogger<Validation>) should consult property.GetValueConverter() (and, by extension, the resulting provider-side type mapping) before declaring the property unmapped. The EF Core 9 relational validator effectively did this; the EF Core 10 rewrite dropped the check.

A targeted fix could be:

IConventionProperty conventionProperty = structuralType.GetDeclaredProperties()
    .FirstOrDefault(p =>
        (!ConfigurationSource.Convention.Overrides(p.GetConfigurationSource())
            || !p.IsImplicitlyCreated())
        && p.FindTypeMapping() == null
        && p.GetValueConverter() == null);  // <-- new clause

This restores the EF Core 9 behaviour: properties with a registered ValueConverter are not flagged as "no type mapping", because the converter establishes the mapping to a supported provider type.

Suggested labels
  • bug
  • area: model validation
  • severity: high
  • affects: 10.0.0
Related
  • OpenMU ffuhr91/OpenMU@fix/npgsql-validator-localizedstring — a working IModelValidator subclass that catches this diagnostic so the game server can boot while the upstream issue is open.
  • I also plan to file a separate report on the EF Core 10 SQL-generation regression that references a non-existent ItemDefinitionTempId3 column when serializing the OpenMU GameConfiguration aggregate.
Lingua principale
C#
Stelle
1.8k
Fork
268
Merge medio
2h 35m
PR unite (30g)
136

Preparare l'ambiente

Questo progetto non fornisce container di sviluppo, Dockerfile né guida per i contributori, quindi l'ambiente è a tuo carico: parti dal suo README e consulta la nostra guida al primo contributo per i passaggi generali.

Come iniziare

  1. Leggi tutta la issue e poi la guida ai contributi del progetto.
  2. Commenta sulla issue per dire che te ne occupi tu — evita che due persone facciano lo stesso lavoro.
  3. Fai un fork del repository e lavora su un branch.
  4. Apri una pull request che faccia riferimento al numero della issue.

Altre issue di npgsql/efcore.pg

Tutte le issue di npgsql/efcore.pg

Issue simili

Altre issue su C#

Ricevi le nuove issue nella tua casella

Un breve riepilogo di issue GitHub adatte ai principianti.